Table 1.

Demographic and clinic characteristics

COPD cases, N (%)Number of controls
CharacteristicsWith lung cancer (N = 432)Without lung cancer (N = 188)Total (N = 620)(%; without COPD and lung cancer) N = 893PaPbPcPd
Sex
 Male240 (55.56)82 (43.62)322 (51.94)348 (38.97)0.008<0.0010.271<0.001
 Female192 (44.44)106 (56.38)298 (48.06)545 (61.03)
Age ± SD, y66.99 ± 8.5467.27 ± 9.6767.08 ± 8.8964.97 ± 9.970.731<0.0010.004<0.001
Smoking status
 Never31 (7.18)29 (15.43)60 (9.67)564 (63.16)0.004<0.001<0.001<0.001
 Former217 (50.23)94 (50.00)311 (50.16)195 (21.84)
 Current184 (42.59)65 (34.57)249 (40.16)134 (15.01)
Pack-years
 0 and never-smoker31 (7.18)33 (17.55)64 (10.32)570 (63.83)<0.001<0.001<0.001<0.001
 1–2029 (6.71)15 (7.98)44 (7.10)32 (3.58)
 21–4075 (17.36)43 (22.87)118 (19.03)121 (13.55)
 >40297 (68.75)97 (51.60)394 (63.55)170 (19.04)
  • aP value for the comparison between COPD cases with and without lung cancer.

  • bP value for the comparison between COPD cases with lung cancer and controls.

  • cP value for the comparison between COPD cases without lung cancer and controls.

  • dP value for the comparison between all COPD cases and controls.